find_path(EIGEN3_INCLUDE_DIR eigen3)
if (EIGEN3_INCLUDE_DIR)
    set(EIGEN3_FOUND ON)
    set(EIGEN3_INCLUDE_DIR ${EIGEN3_INCLUDE_DIR}/eigen3)
    set(EIGEN3_LIBRARY)
endif (EIGEN3_INCLUDE_DIR)

if (EIGEN3_FOUND)
    if (NOT EIGEN3_FIND_QUIETLY)
        message(STATUS "Found Eigen3 include directory: ${EIGEN3_INCLUDE_DIR}")
    endif (NOT EIGEN3_FIND_QUIETLY)
else(EIGEN3_FOUND)
    if (EIGEN3_FIND_REQUIRED)
        message(FATAL_ERROR "Could not find Eigen3 include directory")
    endif (EIGEN3_FIND_REQUIRED)
endif(EIGEN3_FOUND)